Les cellules souches embryonnaires (ES) sont porteuses de grands espoirs en recherche biomédicale dans le but d’apporter un traitement définitif à l’ostéoarthrose. Parce que certaines articulations des chevaux sont similaires à celles des humains, cet animal représente un modèle important dans l’évaluation de stratégies de régénération du cartilage. Cependant, pour expérimenter un traitement par les cellules ES chez le cheval, des cellules ES équines (eES) n’ont toujours pas pu être dérivées. Dans ce contexte, l’objectif principal de cette étude est de dériver des lignées de cellules eES. Le premier objectif de notre étude consiste à optimiser la technique de dérivation des cellules eES. Nous démontrons que la lignée de cellules nourricières et le stade de développement des embryons influencent l’efficacité de la technique de dérivation tandis que l’inhibition de voies de signalisation menant à la différenciation des cellules ES ne l’influence pas sous nos conditions. Le deuxième objectif de notre étude est de caractériser de façon plus approfondie les lignées de cellules eES obtenues. Nous démontrons que les cellules eES dérivées expriment autant des marqueurs associés aux cellules pluripotentes qu’aux cellules différenciées et que l’inhibition de voies de signalisation menant à la différenciation n’influence pas l’expression de ces marqueurs. Pour conclure, nous confirmons avoir dérivé des lignées de cellules semblables au cellules eES (eES-like) ne correspondant pas complètement aux critères des cellules ES. / Embryonic stem (ES) cells carry high hopes for biomedical research in order to provide definitive treatment for osteoarthritis. The horse is considered to be an important animal model for examining osteoarthritis treatments. However, despite almost thirty years of research, authentic equine ES (eES) cells have not yet been derived. In this context, the main objective of this study was to derive eES cell lines. The first objective of our study was to optimize the technique for deriving eES cells. We show that different feeder cell lines and embryo development stages influence the effectiveness of this technique while the use of cell signalling inhibitors does not influence eES cell derivation. The second objective was to characterize markers of pluripotency and differentiation in eES cell lines by RT-PCR. We demonstrate that the eES cells express both markers associated with pluripotent cells and differentiated cells and that the presence of cell signalling inhibitors in the culture medium does not influence the expression of these markers. In conclusion, we confirm having derived eES-like cells but these do not meet all the molecular criteria of authentic ES cells.

O presente estudo visa analisar as operações de cross hedge dos preços do bezerro na Bolsa de Mercadorias & Futuros (BM&F). Para tanto, foram calculados o risco de base destas operações nas semanas de vencimento do contrato futuro de boi gordo, as razões de hedge ótimas e as respectivas efetividades, entre setembro de 1995 e fevereiro de 2001, nas principais praças de comercialização de gado bovino do País - Araçatuba (SP), Bauru/Marília (SP), São José do Rio Preto (SP), Presidente Prudente (SP), Três Lagoas (MG), Triângulo Mineiro (MG), Campo Grande (MS) e Noroeste do Paraná. Como forma de comparação, as mesmas análises foram realizadas para o hedge do boi gordo. O valor médio da base e o risco de base do hedge do boi gordo e do cross hedge do bezerro foram calculados nas semanas de vencimento dos 58 contratos futuros de boi gordo e análises econométricas foram realizadas. Nesta primeira etapa, foi possível observar os seguintes resultados: i) valor médio e variância da base do bezerro foram superiores à do boi gordo em todas as regiões; ii) o desvio padrão da base do boi gordo foi 80,67% inferior ao desvio padrão do bezerro; iii) o risco de base do boi gordo foi estatisticamente inferior nas regiões que compõem o Indicador de Preço Disponível do Boi Gordo - IBG, calculado pelo CEPEA/FEALQ; iv) o risco de base do bezerro não apresentou diferenças estatisticamente significativas entre as regiões. Em uma segunda etapa, o estudo buscou analisar as razões ótimas e a efetividade do hedge do boi gordo e do cross hedge do bezerro, conforme a metodologia de Myers & Thompson (1989). Tanto no cross hedge, como também no own hedge, as razões se mostraram elevadas - no primeiro caso esteve entre 37% e 49%, já no segundo variou entre 58% a 63%. Com relação à efetividade, constatou-se que no caso do own hedge, o risco de preço pode ser reduzido em cerca de 50% com a tomada de posição em contratos futuros de boi gordo na proporção de hedge ótima. No entanto, para o cross hedge, a efetividade foi bastante baixa para todas as regiões, de aproximadamente 1,5%. Se por um lado, a proteção contra os riscos de preço do boi gordo ocorre de forma eficiente, por outro lado a proteção contra movimentos adversos nos preços do bezerro possui baixa efetividade. Conclui-se, portanto, que os pecuaristas, os quais utilizam o preço do bezerro e a relação de troca entre boi gordo e bezerro para a decisão de venda do gado, não possuem um instrumento eficiente, nos mercados futuros, de proteção dos preços de sua atividade. / The aim of the present study is to analyze the cross hedge operation for calves in the BM&F future markets. The basis risk of these operations during the contract maturity weeks were calculated, as well as the optimal hedge ratios and the respective effectiveness. The period considered was September, 1995 to February, 2001, and the regions were chosen according to their importance in commercialization of bovine cattle: Araçatuba (SP), Bauru/Marília (SP), São José do Rio Preto (SP), Presidente Prudente (SP), Três Lagoas (MG), Triângulo Mineiro (MG), Campo Grande (MS) and Noroeste do Paraná. For the sake of comparisons, the same analyses were carried for the fed cattle hedge operations, in the same regions. The average value of the basis and the basis risk of fed cattle hedge and calf cross hedge was calculated for 58 future contracts, in the last week of contract life, and econometric analyses were performed. The main results arising from the preceding analyses can be pointed out: i) average basis value and basis risk of calf were higher than the values of fed cattle in all regions; ii) the basis standard deviation for fed cattle was 80,67% lower than for calf; iii) the regions comprised by IBG, calculated by the CEPEA/FEALQ, showed lower fed cattle basis risk compared to the other regions under study; iv) the calf basis risk in the regions studied did not present statistically significant differences. In a second stage, the study analyzed the optimal hedge ratio and the related effectiveness of own and cross hedge, according to the methodology proposed by Myers & Thompson (1989). The estimated hedge ratio was high in both cases, between 37% and 49% for the optimal hedge ratio and 58% to 63% for the cross hedge. The own hedge figures mean a 50% reduction in price risk when hedging at the optimal ratio, a value that drops consistently to about 1,5% for all regions when the cross hedge is considered. The main conclusion of the study is that the BM&F fed cattle future markets are quite effective as a price risk reduction strategy for the own hedge operations, but lack effectiveness in this sense for the calves cross hedge. Market agents trying to use the calf price and the exchange relation between fed cattle and calf prices for cattle selling decisions should not rely on this mechanism for price risk reductions.

Aquatic sediments are, by surface, the largest habitat on Earth. A wide diversity of organisms inhabit these sediments and by their actions they have a large influence on and also mediate many ecosystem processes. Several of these processes, such as decomposition and remineralisation of organic matter are important on a global scale and are essential to sustain life on Earth. The main aim of this thesis was to use an experimental ecosystem ecology approach in order to study some of these ecosystem processes in marine sediments and how they are linked to biodiversity. Paper I and II found that an increased species richness of sediment deposit feeders increases the processing of organic matter from phytoplankton settled on the sea-floor, and that species-rich communities have a more efficient resource utilization of deposited organic matter. The results in paper IV and V also suggest that there is a link between microbial diversity in sediments and the degradation of organic contaminants. Paper V also shows that antibiotic pollution is a potential threat to natural microbial diversity and microbially mediated ecosystem services. The introduction of invasive species to ecosystems is another major threat to biodiversity and was studied in Paper II and III, by investigating the ecology of Marenzelleria arctia, a polychaete worm recently introduced in the Baltic Sea. Paper II suggests that M. arctia mainly utilize food resources not used by native deposit feeders, thus potentially increasing the benthic production in the Baltic Sea by increasing resource use efficiency. Paper III, however, show that M. arctia is protected from predation by the native benthic invertebrate predators, due to its ability to burrow deep in the sediment, suggesting that predation on M. arctia by higher trophic levels is restricted, thereby limiting trophic transfer. In conclusion, this thesis gives some examples of the importance of marine biodiversity for the generation of a few key ecosystem processes, such as organic matter processing and the degradation of harmful contaminants. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: In press.

Les cellules souches embryonnaires (ES) sont porteuses de grands espoirs en recherche biomédicale dans le but d’apporter un traitement définitif à l’ostéoarthrose. Parce que certaines articulations des chevaux sont similaires à celles des humains, cet animal représente un modèle important dans l’évaluation de stratégies de régénération du cartilage. Cependant, pour expérimenter un traitement par les cellules ES chez le cheval, des cellules ES équines (eES) n’ont toujours pas pu être dérivées. Dans ce contexte, l’objectif principal de cette étude est de dériver des lignées de cellules eES. Le premier objectif de notre étude consiste à optimiser la technique de dérivation des cellules eES. Nous démontrons que la lignée de cellules nourricières et le stade de développement des embryons influencent l’efficacité de la technique de dérivation tandis que l’inhibition de voies de signalisation menant à la différenciation des cellules ES ne l’influence pas sous nos conditions. Le deuxième objectif de notre étude est de caractériser de façon plus approfondie les lignées de cellules eES obtenues. Nous démontrons que les cellules eES dérivées expriment autant des marqueurs associés aux cellules pluripotentes qu’aux cellules différenciées et que l’inhibition de voies de signalisation menant à la différenciation n’influence pas l’expression de ces marqueurs. Pour conclure, nous confirmons avoir dérivé des lignées de cellules semblables au cellules eES (eES-like) ne correspondant pas complètement aux critères des cellules ES. / Embryonic stem (ES) cells carry high hopes for biomedical research in order to provide definitive treatment for osteoarthritis. The horse is considered to be an important animal model for examining osteoarthritis treatments. However, despite almost thirty years of research, authentic equine ES (eES) cells have not yet been derived. In this context, the main objective of this study was to derive eES cell lines. The first objective of our study was to optimize the technique for deriving eES cells. We show that different feeder cell lines and embryo development stages influence the effectiveness of this technique while the use of cell signalling inhibitors does not influence eES cell derivation. The second objective was to characterize markers of pluripotency and differentiation in eES cell lines by RT-PCR. We demonstrate that the eES cells express both markers associated with pluripotent cells and differentiated cells and that the presence of cell signalling inhibitors in the culture medium does not influence the expression of these markers. In conclusion, we confirm having derived eES-like cells but these do not meet all the molecular criteria of authentic ES cells.

Voltage imbalance in low voltage (LV) networks is expected to deteriorate as low carbon technologies, e.g. electric vehicles (EVs) and heat pumps (HPs) are increasingly deployed. The new electrical demand attributable to EVs and HPs would increase the voltage magnitude variation, increasing the possibility of voltages moving outside the statutory LV magnitude limits. Moreover, the single-phase nature of EVs and HPs, which will be connected via a single-phase 'line & neutral' cable to a 3-phase four-wire LV mains cable buried beneath the street, further entangles this voltage management problem; the non-balanced voltage variations in the three phases boost the levels of voltage imbalance. Excessive voltage imbalance and magnitude variation need to be mitigated to limit their adverse effects on the electric network and connected plant. The voltage imbalance in LV networks is conventionally reduced by reinforcing the network, generally at a high cost. Some modern methods for voltage imbalance mitigation have been introduced in recent years. The power electronic converter based methods are inadequate due to the generation of harmonics, significant power losses and short lifetime. Besides, automatic supply phase selection and smart EV charging rely on an advanced smart communication system, which currently is not available. This project aims to develop alternative solutions that mitigate the voltage imbalance seen in LV networks. A voltage balancing method based on Scott transformer (ST) is proposed. This method does not generate harmonics and is independent of the smart communication system. Computer simulations demonstrated the proposed method is able to convert a non-balanced 3-phase voltage into a balanced 3-phase voltage at either a point on the LV feeder or a 3-phase load supply point with the predefined voltage magnitude. Besides, a physical voltage balancing system was created based on the proposed method and it was tested in an LV network in the laboratory. The test results show the balancing system is capable of maintaining a low level of voltage imbalance on the LV feeder by rapidly compensating for the voltage rises and sags caused by single-phase load variations. This voltage balancing method is a potential solution for the network utilities to accommodate the significant penetration of low carbon technologies without breaching the network voltage limits. The impact of EVs and HPs on the LV network voltages is investigated based on a Monte Carlo (MC) simulation platform, which comprises a statistical model of EV charging demand, profiles generators of residential and HP electrical demand, and a distribution network model. The MC simulation indicates the impact of EVs and HPs is related to their distribution; when more than 21EVs and 13HPs are non-evenly distributed on a 96-customer LV feeder, the voltage limits are likely to be violated. Moreover, the effectiveness of the ST based voltage balancing method and the demand response based TOU tariff, implemented either alone or together, in mitigating the impact of EVs and HPs is investigated based on the established MC simulation platform. The results indicate the ST based balancing method alone is able to completely mitigate the voltage limit violations regardless of the penetration levels of EVs and HPs. Moreover, using both of the two investigated methods further enhances the balancing effectiveness of the ST based voltage balancing method.

This experiment was conducted in two zoos - ZOO Troja in Prague and ZOO Ohrada in Hluboká nad Vltavou. The animals were presented the food enrichment of a puzzle type with different difficulties. Solving each levels of puzzles was being compared with the dominance of individuals in the group that was being observed by the aggression among all examinees. Nosal and their accession to the normal diet. All data were statistically evaluated. With the obtained results, the theory of "index of balance in the group" was tested.

O presente estudo visa analisar as operações de cross hedge dos preços do bezerro na Bolsa de Mercadorias & Futuros (BM&F). Para tanto, foram calculados o risco de base destas operações nas semanas de vencimento do contrato futuro de boi gordo, as razões de hedge ótimas e as respectivas efetividades, entre setembro de 1995 e fevereiro de 2001, nas principais praças de comercialização de gado bovino do País - Araçatuba (SP), Bauru/Marília (SP), São José do Rio Preto (SP), Presidente Prudente (SP), Três Lagoas (MG), Triângulo Mineiro (MG), Campo Grande (MS) e Noroeste do Paraná. Como forma de comparação, as mesmas análises foram realizadas para o hedge do boi gordo. O valor médio da base e o risco de base do hedge do boi gordo e do cross hedge do bezerro foram calculados nas semanas de vencimento dos 58 contratos futuros de boi gordo e análises econométricas foram realizadas. Nesta primeira etapa, foi possível observar os seguintes resultados: i) valor médio e variância da base do bezerro foram superiores à do boi gordo em todas as regiões; ii) o desvio padrão da base do boi gordo foi 80,67% inferior ao desvio padrão do bezerro; iii) o risco de base do boi gordo foi estatisticamente inferior nas regiões que compõem o Indicador de Preço Disponível do Boi Gordo – IBG, calculado pelo CEPEA/FEALQ; iv) o risco de base do bezerro não apresentou diferenças estatisticamente significativas entre as regiões. Em uma segunda etapa, o estudo buscou analisar as razões ótimas e a efetividade do hedge do boi gordo e do cross hedge do bezerro, conforme a metodologia de Myers & Thompson (1989). Tanto no cross hedge, como também no own hedge, as razões se mostraram elevadas - no primeiro caso esteve entre 37% e 49%, já no segundo variou entre 58% a 63%. Com relação à efetividade, constatou-se que no caso do own hedge, o risco de preço pode ser reduzido em cerca de 50% com a tomada de posição em contratos futuros de boi gordo na proporção de hedge ótima. No entanto, para o cross hedge, a efetividade foi bastante baixa para todas as regiões, de aproximadamente 1,5%. Se por um lado, a proteção contra os riscos de preço do boi gordo ocorre de forma eficiente, por outro lado a proteção contra movimentos adversos nos preços do bezerro possui baixa efetividade. Conclui-se, portanto, que os pecuaristas, os quais utilizam o preço do bezerro e a relação de troca entre boi gordo e bezerro para a decisão de venda do gado, não possuem um instrumento eficiente, nos mercados futuros, de proteção dos preços de sua atividade. / The aim of the present study is to analyze the cross hedge operation for calves in the BM&F future markets. The basis risk of these operations during the contract maturity weeks were calculated, as well as the optimal hedge ratios and the respective effectiveness. The period considered was September, 1995 to February, 2001, and the regions were chosen according to their importance in commercialization of bovine cattle: Araçatuba (SP), Bauru/Marília (SP), São José do Rio Preto (SP), Presidente Prudente (SP), Três Lagoas (MG), Triângulo Mineiro (MG), Campo Grande (MS) and Noroeste do Paraná. For the sake of comparisons, the same analyses were carried for the fed cattle hedge operations, in the same regions. The average value of the basis and the basis risk of fed cattle hedge and calf cross hedge was calculated for 58 future contracts, in the last week of contract life, and econometric analyses were performed. The main results arising from the preceding analyses can be pointed out: i) average basis value and basis risk of calf were higher than the values of fed cattle in all regions; ii) the basis standard deviation for fed cattle was 80,67% lower than for calf; iii) the regions comprised by IBG, calculated by the CEPEA/FEALQ, showed lower fed cattle basis risk compared to the other regions under study; iv) the calf basis risk in the regions studied did not present statistically significant differences. In a second stage, the study analyzed the optimal hedge ratio and the related effectiveness of own and cross hedge, according to the methodology proposed by Myers & Thompson (1989). The estimated hedge ratio was high in both cases, between 37% and 49% for the optimal hedge ratio and 58% to 63% for the cross hedge. The own hedge figures mean a 50% reduction in price risk when hedging at the optimal ratio, a value that drops consistently to about 1,5% for all regions when the cross hedge is considered. The main conclusion of the study is that the BM&F fed cattle future markets are quite effective as a price risk reduction strategy for the own hedge operations, but lack effectiveness in this sense for the calves cross hedge. Market agents trying to use the calf price and the exchange relation between fed cattle and calf prices for cattle selling decisions should not rely on this mechanism for price risk reductions.

This work will describe current distribution measurement problems along antenna conductor using a probe (coupling loop), which is attached to selective micro-voltmeter, which will indicate signal level (voltage). The signal level will be used for representing the current distribution. Subsequently, measuring workplace issues from generator to antenna conductor, probe and selective micro-voltmeter, will be discussed. Analysis of voltages of this link-up and additional study will be conducted. Other parameters, which complement this situation, will be calculated from the current distribution. A computer program, which calculates these parameters and speeds up the collected data processing, will be used for this process.

The main subject of the diploma thesis „Contradiction analysis of small water power Ostravice“ is solution of reduced output of small water power plant on the river Ostravice near the town Vratimov. Power plant equippment is axial flow Kaplans turbine RA – 3,5 – 0 1000 with runner diametr 1000 mm. Low output is caused by draft tube. New draft tube is designed in this masters thesis. For hydraulic layout was used CFD software Fluent. The aim of this work is finding of optimal shape which leads to increasing of power from current 30 kW to projected 55 kW.

The thesis proposes a workplace automatic assembly O-rings on the pneumatic valve. It was designed mechanism assembly, assembly testing, movement to test for leaks, flow measurement, transport valve through the workplace and economic calculation workplace.